Brain 17 Vienna

07.11.2017

New risk stratification since 2016

Other embryonal tumors

• Dismissal of PNET, primitive neuroectodermal tumor • Instead: • C19MC -amplified Embryonal tumor with multilayered rosettes • ETANTR + ependymoblastoma + medulloepithelioma • Immunohistochemical marker LIN28 • Atypical teratoid/rhabdoid tumor (AT/RT) • defined by INI1 or very rarely BRG1 • Immunohistochemical marker SMARCB1/INI1 • Wastebasket category for all others: CNS embryonal tumor, NOS

Kuzan-Fischeretal,ClinicalNeurosurgery,2017

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Other tumors: Ependymoma

Neuronal and mixed neuronal-glial tumors

• WHO grading of unclear clinical significance

Diffuse leptomeningeal glioneuronal tumor • Mostly in children

• One narrowly defined subgroup: Ependymoma, RelA gene fusion • Drives NFkappaB signaling (outside of the mutation box!) • Majority of supratentorial tumors in children, poor prognosis! • L1CAM expression as immunohistochemical surrogate

and adolescents • Histologically reminiscent of oligodendroglioma

BRAF-KIA gene fusion

1p del

Louiset al, Acta Neuropath 2016

New diagnostic entity

MParker et al.Nature (2014)

New diagnostic entity

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Meningioma

Solitary fibrous tumor - hemangiopericytoma

• Classification and grading not revised

• Soft tissue pathologists moved away from the designation hemangiopericytoma

• Except: brain invasion as a criterion for atypical meningioma, WHO grade II • Mitotic count (5 mitoses per 10 high-power fields) or • Brain invasion is sufficient

• Considered within the spectrum of solitary fibrous tumors

• Both share genetic constellations, most notably STAT6 gene fusion -> one common entity • Grade I-III • Grade I: highly collagenous, low cellularity • Grade II: more cellular, less collagenous „staghorn“ vessels • Grade III: + 5 mitoses per 10 high-power fields

NEW

Brain invasion

Mitotic count

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